Goulds Pumps API 3171 - IOM - Manual (Page 29)

Check Explanation/comment Checked
Use cushioning devices. This protects the pump from surges and water hammer
if quick-closing valves are installed in the system.
Alignment criteria for pump flanges
Type Criteria
Axial The flange gasket thickness is ±0.03 in. (0.8 mm).
Parallel Align the flange to be within 0.001 in./in. to 0.03 in./in. (0.025 mm/mm to 0.8 mm/mm) of
the flange diameter.
Concentric You can easily install the flange bolts by hand.
Suction piping for optional dry pit, outside tank mount, and tailpipe
applications
Checklist
Check Explanation/comment Checked
Install an elbow at the pump. Whenever possible, perform these actions:
• Use long radius elbows.
• Move the elbow further from the suction.
• Eliminate unneeded elbows.
Make sure the suction piping is a larger
diameter than the pump suction.
—
Install separate suction lines when more
than one pump is operating from the same
source of supply.
—
Make sure that the suction piping contains
no air pockets.
—
Make sure that the suction piping slopes
upwards toward the pump.
—
Make sure that all joints are air tight. —
Provide a method to prime the pump. For outside tank mount and dry pit applications,
allow the fluid level inside the tank or pit to rise
above the casing level.
In tailpipe applications, submerge the casing
before you start the pump.
For outside tank mount and dry pit
applications, install an isolation valve in the
suction line at least two pipe diameters
from the suction.
This allows the line to be closed for pump
inspection and maintenance. The isolation valve
must be kept fully open during operation.
Make sure that the entrance to the suction
pipe is kept adequately submerged below
the free liquid surface.
This prevents vortices and air entrainment.
For an outside tank mount application,
make sure that a column assembly is
installed.
The column assembly allows the fluid that comes
through the lower bushings to flow up through the
column and back through the connection at the
top of the column back to the tank.
Connect the pipe at the top of the pump column
back to the source tank in order to prevent fluid
from entering the thrust bearing.
Installation
Model API 3171 Installation, Operation, and Maintenance Manual 27